Here's the story: over the last six months or so my wife's daily driver Santa Fe (2.0T) with original OEM battery (4+ years old) would start fine, get her to work and then at quitting time she'd find a dead battery, requiring a boost to get going again. She admitted leaving interior lights on a couple times which I figured caused the dead battery. This has happened three times total, the last time being last week. Given the age of the battery and the number of total discharges it's had, I decided to replace the battery with a Duracell 124R which is a perfect replacement for the OEM unit and it has slightly better performance numbers than the original. I should have tested the charging system before replacing the battery, but I didn't.
I've since done some tests with my multi-meter on a few occasion just to get a feel for what "normal" is for the charging system. The numbers I've seen (with the new battery) is as follows (all measurements across the battery):
After sitting over night, engine OFF: 12.65V
After sitting over night, engine ON: 14.44V (a few seconds after start-up, at low idle)
Fast idle (2000 RPMs a few minutes after start): 14.42V
Here's the weird instance that I have a question about: I checked the voltage after a recent short trip around town (engine ON at idle AND at 2000 RPMs) and the voltage read 12.67V, which I found odd. There were NO malfunction lights showing on the panel. I expected to see a charging voltage above 14V. After the next start-up, the numbers were back to the above readings. My question is: would the voltage regulator ever normally cycle the alternator off completely, as it would appear happened by this voltage reading? I've since had Autozone check the charging system with their diagnostic device and they said everything passed.
Do I have an intermittent charging system malfunction that's randomly killing the battery, or is this normal operation for a late model Hyundai?
--Rob
I've since done some tests with my multi-meter on a few occasion just to get a feel for what "normal" is for the charging system. The numbers I've seen (with the new battery) is as follows (all measurements across the battery):
After sitting over night, engine OFF: 12.65V
After sitting over night, engine ON: 14.44V (a few seconds after start-up, at low idle)
Fast idle (2000 RPMs a few minutes after start): 14.42V
Here's the weird instance that I have a question about: I checked the voltage after a recent short trip around town (engine ON at idle AND at 2000 RPMs) and the voltage read 12.67V, which I found odd. There were NO malfunction lights showing on the panel. I expected to see a charging voltage above 14V. After the next start-up, the numbers were back to the above readings. My question is: would the voltage regulator ever normally cycle the alternator off completely, as it would appear happened by this voltage reading? I've since had Autozone check the charging system with their diagnostic device and they said everything passed.
Do I have an intermittent charging system malfunction that's randomly killing the battery, or is this normal operation for a late model Hyundai?
--Rob